Magnetic buckle switch

ABSTRACT

Switch in seat belt buckle which operates upon insertion of tongue of buckle and operates under magnetic force when tongue is not inserted in buckle to give signal indication or interlock with ignition.

States Patent 1 MAGNETIC BUCKLE SWITCH Donald J. Lewis, Troy, Mich.

Allied Chemical Corporation, New York, NY.

Filed: Mar. 6, 1972 Appl. No.: 232,042

Inventor:

Assignee:

U.S. C1. 200/6158 B, 335/205, 297/385,

Hnt. Cl. H0111 36/00 Field of Search 200/61.18, 61.58 B; 180/82 C;280/150 SB; 297/388; 340/525 B;

Nov. 6, 1973 [56] References Cited UNITED STATES PATENTS 3,612,79110/1971 Porter et a1 200/6l.l8 3,154,167 10/1964 Butler et al. ZOO/61.58B X 3,147,819 9/1964 Keleher ZOO/61.58 B X Primary Examiner-J. R. ScottAtt0rneyJonathan Plant [57] ABSTRACT Switch in seat belt buckle whichoperates upon insertion of tongue of buckle and operates under magneticforce when tongue is not inserted in buckle to give signal indication orinterlock with ignition.

6 Claims, 5 Drawing Figures MAGNETIC BUCKLE SWITCH This applicationrelates to a magnetic buckle switch to be used in a seat belt bucklearrangement, for example for automotive or aircraft seat beltutilization. More particularly, this invention relates to theintroduction in the buckle part of the seat belt arrangement of amagnetically sensitive switch which when closed when the seat isoccupied will complete a circuit to give signal to the operator of thevehicle that the seat belts are not fastened, or further, in automotivevehicle utilization, will interrupt the ignition circuit of theautomobile so as to not allow operation.

It has been proposed by various arrangements that when the seat belts ofan automobile, for example, are not fastened in a location occupied bythe driver or passenger that a signal, visual and/or audible, and/or aninterlock to the ignition to prevent ignition, be provided for. Suchprovision either in a retractor winding up and storing said seat belt orin the seat belt buckle has previously been proposed, but such proposalsare complicated and require significant modification to the seat beltand retractor structure.

This invention generally provides for the introduction into the seatbelt buckle of a switch, for example in the preferred embodiment a splitreed device, which closes under the influence of a magnet also found inthe buckle. The tongue of the buckle is inserted between the magnet andthe switch device, such that when the tongue is inserted it breaks ordecreases the magnetic force of the magnet on the switch, which thenopens. When the switch is opened, the circuit from the source ofelectric power, the battery for example, to driver awareness means, suchas a warning buzzer, a warning light, and/or a solenoid for opening aswitch in the ingition circuit, for example, is broken and no visual,audible or interlock with the ignition indication occurs, When thetongue is removed from the buckle, the influence of the magnet on theswitch is such that the switch closes and such visual, audible orinterlock with ignition indication as is programmed by the completedcircuit of the closed switch takes place.

The simple circuit utilizing the switch within the buckle may beprovided with a second switch device which is responsive to a switchwithin the seat of the passenger or occupant utilizing the particularseat belt, so that the visual and/or audible indication will only givethe indication of being unbuckled when the occupant is sitting in theseat position utilizing it, and interlock with the ignition will onlythen so occur.

The invention will become clearer with reference to the following moredetailed disclosure of which FIG. 1 is a schematic of a seat belt buckleassembly in which the tongue of the buckle has been inserted;

FIG. 2 is the schematic of FIG. 1 with-the tongue removed;

FIG. 2A is another embodiment;

FIG. 3 is an illustrative circuit, and

FIG. 4 is a simple weight switch which might be utilized in theembodiment disclosed.

According to the invention, a seat belt buckle 1 is shown as attached toseat belt webbing 2. A tongue 3 is shown schematically locked within theseat belt buckle 1, said tongue being attached to the other length ofseat belt webbing 4. Details of one embodiment of such a seat beltbuckle may be found in US. Pat. No. 3,522,640, issued Aug. 4, 1970.Located for example at the edge of the buckle adjacent to where thetongue enters the buckle and on opposite sides of the tongue are amagnet 5 and a switch device 6, mounted within the buckle, for exampleon a pedestal 7. The switch 6 may be enclosed on the pedestal by aplastic shield 8, for example, for protection. The switch comprises inone illustrative embodiment, two flexible metal reeds 9 and 10. When thetongue 3 is within the buckle l as shown in FIG. 1, the magnetic fieldor force of the magnet 5 on the reeds 9 and 10 is insufficient to causethem to contact. When the tongue 3 is not located within the buckle 1,the magnetic field or force on the reeds 9 and 10 is sufficient to bringthe reeds into contact with one another, closing the circuit to giveindication or interlock with the ignition circuit as will be describedhereinafter.

Thus when the seat belt is not fastened, the reed switch is closed andan indication of visual and/or audible signal, and/or interlock to theignition circuit is made. Operation of the vehicle may only be madewithout such signal indication or after such interlock with the ignitioncircuit is removed by fastening the seat belt.

As shown in FIG. 3, the reed switch 7 with its fingers 9 and 10 isconnected to a lamp for indicator 11 which is in turn connected to abattery or other source of electrical current to complete the circuit.The signalling device 11 may be a visual indicator and/or a buzzer, .orother audible indicating means. Furthermore, the indicator 11 may be inthe form of a circuit interruption or other device to open the ignitioncircuit or otherwise make ignition impossible, such as a solenoid, forexample, which when the switch 7 is closed is energized by completion ofthe circuit to open a switch in the ignition circuit, not shown, so thatignition of the vehicle may not be undertaken until the switch 7 isopen. Thus, the indicator 11 in the circuit diagram of FIG. 3 may be thevisual, audible or interlock means for interconnection to the ignitioncircuit, or a combination of two or all three. Obviously, thesolenoid-powered breaking of the ignition circuit is only one way inwhich to interlock the seat belt buckling with the ignition circuit.

As shown in FIG. 3, optionally included within the circuitry may be aswitch 12 which closes to complete the circuit responsive to activationof a switch found within the seat on which the occupant or driver usingthe particular seat belt is sitting, so that the seat belt buckle switchwill 'only have an effect on the visual and- /or audible indication orthe ignition interlock if an occupant or the driver is in fact sittingin the position utilizing the seat belt.

A seat switch 13 of the type described in the preceding paragraph isshown within the seat 14 such that when an occupant sits in the seatingposition on the seat 14 to use the seat belt buckle l the weight of hisbody on the cushion 15 will depress and close the switch 13 against theforce of spring contact 16 (against contact plate 17) and thus close theswitch 12. Then, after sitting in position 15, if the occupant orpassenger does not latch the seat belt 1 so that the tongue 2 interruptsthe magnetic flux or force between the magnet 5 and the reed switch 7,the visual and/or audible indication, and/or ignition interlock willtake place. When an occupant is not sitting on the seat 14 in theposition 15 over the seat switch, the switch 12 will be open and thecircuit shown in FIG. 3 will have no bearing on visual or audibleindications or the starting of the ignition of the vehicle.

The circuitry of FIG. 3, as well as the particular switch shown in FIG.4 are illustrative of one operative embodiment of the invention, but notmeant to limit the invention. The seat belt buckle of FIGS. 1 and 2 areshown in schematic form in order to illustrate the introduction of thetongue to break off the magnetic influence over the switch. Theparticular switch shown in FIGS. 1 and 2 is highly advantageous, as isthe placement of the magnet and switch near the point of entry of thetongue, since they are removed from the structure which locks the tongueinto the buckle. Of course, the arrangement may be reversed so thatinsertion of the buckle causes closing of the switch, as shown in FIG.2A, as by, for example, inclusion of a second magnet 20 whose force onthe switch is great enough to contact reeds 9 and 10 when the tongue 3interrupts the force of the magnet 5. In such an embodiment, the openingof the switch 6 causes the signal to occur. The location of the switchand magnet near the webbing end of the buckle, as shown in FIG. 2A, forexample, requires the switch to be operated on buckling.

It is meant that the invention only be limited to the scope of thefollowing claims.

I claim:

1. A safety seat belt assembly in a vehicle with driver awareness meansfor indication to the driver that the safety seat belt has not beenbuckled, which comprises:

a. a buckle connected to a first section of seat belt webbing, saidwebbing being attached to the vehicle;

b. a tongue connected to a second section of seat belt webbing, saidwebbing being attached to the vehicle;

c. an opening in said buckle into which said tongue is inserted;

d. a latch bar in said buckle for engaging and locking the tongue wheninserted in the opening of the buckle;

e. a release button in said buckle for release of the latch bar topermit the tongue to be withdrawn from the buckle;

f. switch means mounted in said buckle, said switch means having twooperable positions; and

g. magnet means comprising a magnet disposed in the buckle on the sideopposite the switch with the tongue when inserted in the buckleinterposed between the magnet and the switch, said switch means being inone operable position under the force of said magnet when the tongue isnot inserted in said buckle and being in a second operable position whensaid tongue is interposed between the magnet and the switch.

2. Apparatus as claimed in claim 1, said switch designed to open underthe force of the magnet means when the tongue is inserted.

3. Apparatus as claimed in claim 1, said switch de signed to close underthe force of the magnet means when the tongue is inserted.

4. Apparatus as claimed in claim 3, said magnet means comprising amagnet located on the opposite side of the buckle in relation to thetongue from said switch and a magnet on the same side of the buckle inrelation to the tongue as said switch, said magnet on the opposite sideof the buckle causing said switch to open under the magnetic force whenthe tongue is not inserted and said magnet on the same side of thebuckle as the switch causing said switch to close when the tongue isinserted and the force of the first named magnet is therefore lessened.

5. Apparatus as claimed in claim 4, said switch means comprising tworeeds spaced apart.

6. Apparatus as claimed in claim 5, said magnet means and reeds locatedadjacent to the webbing end of the buckle thereby requiring operation ofthe switch means as the tongue is engaged.

1. A safety seat belt assembly in a vehicle with driver awareness meansfor indication to the driver that the safety seat belt has not beenbuckled, which comprises: a. a buckle connected to a first section ofseat belt webbing, said webbing being attached to the vehicle; b. atongue connected to a second section of seat belt webbing, said webbingbeing attached to the vehicle; c. an opening in said buckle into whichsaid tongue is inserted; d. a latch bar in said buckle for engaging andlocking the tongue when inserted in the opening of the buckle; e. arelease button in said buckle for release of the latch bar to permit thetongue to be withdrawn from the buckle; f. switch means mounted in saidbuckle, said switch means having two operable positions; and g. magnetmeans comprising a magnet disposed in the buckle on the side oppositethe switch with the tongue when inserted in the buckle interposedbetween the magnet and the switch, said switch means being in oneoperable position under the force of said magnet when the tongue is notinserted in said buckle and being in a second operable position whensaid tongue is interposed between the magnet and the switch. 2.Apparatus as claimed in claim 1, said switch designed to open under theforce of the magnet means when the tongue is inserted.
 3. Apparatus asclaimed in claim 1, said switch designed to close under the force of themagnet means when the tongue is inserted.
 4. Apparatus as claimed inclaim 3, said magnet means comprising a magnet located on the oppositeside of the buckle in relation to the tongue from said switch and amagnet on the same side of the buckle in relation to the tongue as saidswitch, said magnet on the opposite side of the buckle causing saidswitch to open under the magnetic force when the tongue is not insertedand said magnet on the same side of the buckle as the switch causingsaid switch to close when the tongue is inserted and the force of thefirst named magnet is therefore lessened.
 5. Apparatus as claimed inclaim 4, said switch means comprising two reeds spaced apart. 6.Apparatus as claimed in claim 5, said magnet means and reeds locatedadjacent to the webbing end of the buckle thereby requiring operation ofthe switch means as the tongue is engaged.